Siaximtjm-demand meter



Aug. 25, 1925; 1,551,284

. W. M. BRADSHAW ET AL MAXIMUM DEMAND METER Filed April 18, 1919 INVENTORS WITNESSES: William M firddshan fl v I J gl ar'encg A. Bodd/e Patented 25, 1925.

* en ree STATE-S- 'i I parent OFFECE;

ILLIAM mannnsmiw, on wILKrNsBUnG; Ann -.GLARENOE A. iBonDrE, or PITTS- B RGH, PENNSYLVANIA, nssrerrons'ro WESTINGHOUSE ELECTRIC & IEZANUFAC- "TU-RING COMPANY, A CORPOR T ON O :B NNSYLYANI To all whom it may) concern:

,-Be it known that we, .lVILLIAM c sHAw, a citizen of the United States, and a' resident ofvlVilkinsburg, in the countyot Allegheny and State of Pennsylvania, and

CLARENCE A. Bonnie, a citizen of the United States, and a resident of Pittsburgh,.in the county of Allegheny and State of Pennsylvan'ia,rhave invented a new and useful Improvement in Maximum Demand Meters, of-

which thevtollowing is a specification.

Our invention relates to electrical measur- 1: ing instruments and particularly to means for varying the torque ofmotor meters in. accordance with the. mechanical load on the movable members thereof; One obJect of our nvention s to torque of a motor meter in accordance with the resistance ,offeredftothe movement of the movable memberthereof that its registration is correctpunder; all conditions of.

- operation.

"Arno her object otourjinventicn is to providea device of the above'indicated character t hat shall. permit aslowly-responsive motor meter to be variously loaded and still correctly indicate the maximum demand.

. A further object of our invention is to provide ,afdevice of the above indicated characterthat shall be simple and inexpensive to constructand effective in its opera tion.

' ifile'd'lOct. 8,1918,

assigned ,to l the 'l/Vesting'house Electric & I

Copending application, SeriaLNo; 257,326, by ,Talter G. Mylius Y and Mfg. Co. discloses an attachment for a motor 4 meter. that comprises a 'spring, oneend-of which is wound by the motor meter and the other end of which is retarded by adamp inginagnet. "A pointer is-actuated in accordance with the ,differential movement of-the twoends of the springand thus con-c V a provide means for so-autom'atically varylng the indicator;

v W A I M- E AND ET & 7 Application a1a'A n1,,1 ,=1aia Vsr ia1 1io.ae 1,1o s.:

r 7 same to'be automatically varied in ac-1 M4 BRAD- co'rdance with the movement; of 'thef 'pointer Y to therebyfshunt magnetic flux from [thea rmatnre' in inverse proportion to the mechanical load therefon. 'Wlth this arrangement, the speed of the armature jwill'not be afiected reason ofth'e tensioning of the spring and,ico-nsequently,"w-ill vary only in accordance with the load traversing the w ndings thereof. 7

Fig. 1 of the accompanying drawings is a front viewof amotor meter embodying our invent on; Fig. 2 1s a top plan view of the, motonmeteri'shown in Fig. 1, and Fig.

8 isar ia'g l tic vi w Of a m ximum-e demand meter embodying our invention;

A-maXimum-demand meter 1, embodying our invention, comprises, in general, a motor meter 2, a spring. 3 that is wound from one end by,t'he v motor meter} and theunwind- I ling: ofgthe other end of which is; controlled by a disk 'and a damping magneto; A.

pointer ,6 isactuated through a differential gearlng 7,1111; accordance withfthe differential movement of the two ends of the spring 8,

and thus indicates, at all times, a value that may be assumed tobe the deniand equivalent ofjthenload; traversing the motor meter 2.

A maximum-demand pointer- 20 is actuated by the pointer ;6.

a Tll efmot'or m ag l l member 8, current and poteneter 2 comprises a stationary tial windings 9rrand l0, respectively andja closed-circuit} winding ,011 member ll that ispivotally mounted for movementqin' the airgap, 12,.0f the lmember' 8'. The winding 11, which consists of a single turn, is pro vided with a lever arm 13; that is connected,

through 'a crankarm l l, to a sl iaft lothat 1am.

is connected,;' through gear members 7 the planetary member 17 of the differential gear-device 7. A spring 18 is provided'for yieldingly biasing the member ll towardsits uppermost position. "@The member 11 -is adapted to be actuated, through the' crank armll, by the planetarymember l'z to permitlmore flux fromithe electromagnet S-"to cutLthearmature' 19 and thus increase. the torque of the same in accordanc'e'withlthe increase in. mechanical load imposed thereon by reason ofthe tensioning of the spring 3.

With this device, the accuracy of 7 motor meter 2 is maintained because its speed does not decrease when the armature the becomes mechanically loaded and, consequently, a meter having a high degree of accuracy is obtained.

Our invention is not limited to the specific structure illustrated, as it may be variously modified without departing from the spirit and scope thereof, as set forth in the ap pended claims.

We claim as our invention:

1. In a watthour meter, the combination with a spring one end of which is connected to the movable member of the meter, means for retarding the movement of the other end of the spring and a pointer actuated in accordance with the differential movement of the ends of the spring, of means actuated in accordance'with the indication of the pointer for varying the torque of the meter to compensate for the torque required to wind the spring.

2. In a watthourmeter, the combination with a movable member, a pointer and a spring disposed between the pointer and the movable member, of a torque varying device for the meter, and means for adjusting the said device in accordance with the tension of the spring.

3. In a meter, the combination with a movable member and a spring wound thereby, of means for varying the torque ofthe movable member in accordance with the load imposed thereon by reason of the tensioning of the spring. 7

4. A motor meter comprising a movable member, a pointer, a spring disposed between the pointer and the movable member and means for varying the torque of the movable member in accordance with the change in the load thereon incident to tensioning the sprin 5. A motor meter comprising the combination with a movable member and means for imposing a variable mechanical load thereon, of a regulating member and means automatically responsive to variations in the mechanical load on the movable member for adjusting the regulating member to cause the speed of the motor meter to correspond to a quantity to be measured.

6. A motor meter comprising the combination with a magnetizable core member, an armature and means for imposing a variable mechanical load thereon, of means for shifting the magnetic flux of the core member with reference to the armature and means for adjusting said shifting means in accordance with changes in the mechanical load on the armature to ensure a speed of the armature corresponding to the electrical load. 7 1 i 7, A motor meter comprising the combination with a magnetizable core member, an armature and means for imposing a variable mechanical load thereon, of means for diverting the magnetic flux passing through the armature and automatic means for adjusting said diverting means to cause the torque of the meter armature to vary in accordance with variations in the mechanical load on the armature.

8. A motor meter comprising the combination with a magnetizable core member, an armature and means for imposing a variable mechanical load thereon, of a closed-circuit winding for diverting the flux from the core member through the armature and means re sponsive to the load on the armature for adjusting said winding to vary the torque developed by the armature in accordance with variations in the mechanical load thereon.

9. A meter comprising a movable operating member, means for actuating the same by forces in accordance with a quantity being measured, an indicating member actuated by said member, means for causing the movable member to operate at all times under predeterminedvarying load, and means for causing the indicating member to accurately indicate the quantity being measured irrespective of said load variations.

10. A meter comprising a movable operating member, means for actuating the same by forces in accordance with a quantity being measured, an indicating member actuated thereby, variable retarding means between the movable member and the indicating member, and means for controlling the torque of the movable member in accordance with variations in retardation of the retard ing means to cause the indicating member to accurately indicate the quantity being measured irrespective of said variations.

11. A meter comprising an operating member, means for actuating the same by WILLIAM M. BRADSHAW. CLARENCE A. BODDIE, 

